Estimate of the Branching Fraction of tau --> pi eta' nu_tau

Abstract

We calculate the expected branching fraction of the second-class-current decay tau --> pi eta' nu, motivated by a a recent experimental upper-limit determination of this quantity. The largest contribution to the branching fraction is due to the intermediate a0(980) scalar meson, assuming it is a $\bar{u}d$ state. Smaller contributions arise from a0(1450), rho(770), and rho(1450). Our calculated values are substantially below the experimental upper limit, and are smaller still if the a0(980) is a four-quark state, as often suggested. Thus, a precise measurement or tight upper limit has the potential to determine the nature of the a0(980), as well as search for new scalar interactions.

4 pages, to be submitted to PRD

References in corpus (3)

• A Theory of Scalar Mesons
• Measurement of the pseudoscalar mixing angle and ${\eta }^{\prime }$ gluonium content with KLOE detector
• Estimate of the branching fraction ${\tau }^{-}\to \eta {\pi }^{-}{\nu }_{\tau }$, the $a_0^{-}(980)$, and non-standard weak interactions

Cited by in corpus (8)

• Effective-field theory analysis of the ${\tau }^{-}\to {\eta }^{(\prime )}{\pi }^{-}{\nu }_{\tau }$ decays
• On the branching ratio of the "second class" tau --> eta' pi nu_tau decay
• Long-lived light neutralinos at Belle II
• ${\tau }^{-}\to {\eta }^{(\prime )}{\pi }^{-}{\nu }_{\tau }\gamma$ decays as backgrounds in the search for second class currents
• G-parity breaking in ${\tau }^{-}\to {\eta }^{(\prime )}{\pi }^{-}{\nu }_{\tau }$ decays induced by the ${\eta }^{(\prime )}\gamma \gamma$ form factor
• Towards the (Mexican) discovery of second class currents at Belle-II
• ${\tau }^{-}\to {\pi }^{-}\eta {\nu }_{\tau }$ decay induced by QED one-loop effects
• The second-class current decays $\tau \to \pi \eta ({\eta }^{\prime }){\nu }_{\tau }$ in the NJL model including the interaction of mesons in the final state